Export (0) Print
Expand All
Expand Minimize

Compiler Error CS0012 

Error Message

The type 'type' is defined in an assembly that is not referenced. You must add a reference to assembly 'assembly'.

The definition for a referenced type was not found. This could occur if a required .DLL file is not included in the compilation. For more information, see Add Reference Dialog Box and /reference (Import Metadata) (C# Compiler Options).

The following sequence of compilations will result in CS0012:

// cs0012a.cs
// compile with: /target:library
public class A {}


// cs0012b.cs
// compile with: /target:library /reference:cs0012a.dll
public class B
   public static A f()
      return new A();


// cs0012c.cs
// compile with: /reference:cs0012b.dll
class C
   public static void Main()
      object o = B.f();   // CS0012

You could resolve this CS0012 by compiling with /reference:b.dll;a.dll.

Community Additions

© 2015 Microsoft